python - Django ChainedForeignKey smart menu -

i trying make chained select menu, have model:

from django.db import models  class health_plan(models.model):     name = models.charfield(max_length=15)  class doctors_list(models.model):     name = models.charfield(max_length=30)     specialty = models.charfield(max_length=15)     health_plans = models.manytomanyfield(health_plan, related_name="doctors")     location = models.charfield(max_length=15)      def __unicode__(self):         return self.name 

and forms.py:

class specform(modelform):     = doctors_list.objects.values_list('specialty', flat=true)     unique = [('---------------','---------------')] + [(i,i) in set(a)]     specialty = forms.choicefield(choices=unique)     class meta:         model = doctors_list  class healthform(modelform):     hplan = chainedforeignkey(         health_plan,          chained_field="specialty",         chained_model_field="specialty",          show_all=false,          auto_choose=true     )    

my urls.py:

from django.conf.urls import patterns, include, url testapp.views import spec_form testapp.views import health_form  django.contrib import admin admin.autodiscover()  urlpatterns = patterns('',     # examples:     url(r'^$', 'medbook.views.home', name='home'),     # url(r'^medbook/', include('medbook.foo.urls')),     url(r'^admin/doc/', include('django.contrib.admindocs.urls')),     url(r'^admin/', include(admin.site.urls)),     url(r'^hello/$',  spec_form, health_form), ) 

and views.py:

from django.shortcuts import render_to_response  testapp.forms import specform testapp.forms import healthform  def spec_form (request):     if request.method == 'post':         form = specform(request.post)         if form.is_valid():             form.save()     else:         form = specform()     return render_to_response('hello.html', {'form':form})  def health_form (request):      if request.method == 'post':         form = healthform(request.post)         if form.is_valid():             form.save()     else:         form = specform()     return render_to_response('hello.html', {'form':form}) 

by error 'function' object not iterable when acess webpage. new django , find tricky. user must select 1 specialty, , should appear health_plans cover specialty.

the health_plans have manytomany relationship doctors. when person chooses specialty, script should check wich doctors belong specialty , retrieve health plans hold doctors.

i hope made clear, code isn't.

any kindly appreciated

edit: stack trace

internal server error: /hello/ traceback (most recent call last): file "c:\python27\lib\site-packages\django\core\handlers\base.py", line 103, in get_response resolver_match = resolver.resolve(request.path_info) file "c:\python27\lib\site-packages\django\core\urlresolvers.py", line 321, in resolve sub_match = pattern.resolve(new_path) file "c:\python27\lib\site-packages\django\core\urlresolvers.py", line 221, in resolve kwargs.update(self.default_args) typeerror: 'function' object not iterable [08/may/2013 19:30:45] "get /hello/ http/1.1" 500 62490

change:

url(r'^hello/$', spec_form, health_form) url(r'^hello/$', spec_form)

also, in models:

class health_plan(models.model):     name = models.charfield(max_length=15)     def __unicode__(self):         return "%s"%(self.name)